This invention generally relates to semiconductor structures, and more specifically, to preventing trench silicide shorts in semiconductor structures.
In the formation of semiconductor devices, it is beneficial to provide both desired electrical contact between certain regions of the devices formed and also to prevent contact between various other regions of the devices formed in the substrate. As the technology advances, allowing for the formation of smaller and smaller devices, it is increasingly difficult to achieve the desired electrical contacts while also preventing undesired electrical shorts from developing.
For instance, in some semiconductor structures, conductive line-type device level contacts are formed between gates. These device level contacts are referred to as trench silicide regions or trench silicides. Insulating spacers are used to separate the trench silicides from the gates. However, as the gate caps are etched, portions of these insulating spacers may also be etched away. Subsequently, when metal is deposited on the gate, metal may fill some of the space previously filled by the etched away spacer and form an undesired electrical contact, or short, between the trench silicide and the gate. The above-described processing is performed in the middle of the procedure used to fabricate the semiconductor structure, and thus the above-discussed shorts are referred to as middle-of-line contact shorts.